i 



m: 



ESSENTIALS IN 
MECHANICAL DRAWING 



THE MACMILLAN COMPANY 

NEW YORK • BOSTON • CHICAGO • DALLAS 
ATLANTA • SAN FRANCISCO 

MACMILLAN & CO., Limited 

LONDON • BOMBAY • CALCUTTA 
MELBOURNE 

THE MACMILLAN CO. OF CANADA, Ltd. 

TORONTO 



ESSENTIALS 



IN 



MECHANICAL DRAWING 



BY 



L. J. SMITH, B.S. 



PROFESSOR OF AGRICULTURAL ENGINEERING, MANITOBA AGRICULTURAL 

COLLEGE ; FORMERLY INSTRUCTOR IN CHARGE OF THE DIVISION 

OF FARM MECHANICS, MICHIGAN AGRICULTURAL 

COLLEGE ; MEMBER OF THE AMERICAN 

SOCIETY OF AGRICULTURAL 

ENGINEERS 



THE MACMILLAN COMPANY 
1917 

All rights reserved 






Copyright, 1917, 
By the MACMILLAN COMPANY. 



Set up and electrotyped. Published May, 1917. 



-0 





MAY 10 1917 



.1. S. Gushing Co. — Berwick & Smith Co. 
Norwood, Mass., XT.B.A. 



^CI,A4G0653 



PREFACE 

This brief treatment of the essentials of mechanical 
drawing is designed to give instruction in the rudiments of 
plan drawing as it occurs in everyday life, so that the student 
will be able to read and understand ordinary drawings 
and be able to do ordinary mechanical sketching. The 
book should be of value also to one who is about to take 
a longer course in drawing, for it aims to correct the com- 
mon mistakes of the beginner. 

Where work is given without the regular instruments, 
it is well to provide the students with small drawing boards 
about 12 X i8 inches in size, together with a T square. 
This equipment makes for more rapid and accurate work. 
The bottom edge of the drawing board can be planed 
square with the left side so that the T square may be used 
for both horizontal and vertical lines. 

The lists of exercises offered are merely suggestive. 
Where possible it is best to have drawings made from the 
object itself rather than from another drawing. This is 
possible even in the drafting room, in institutions where 
shop work is given, for one can there secure enough joints or 
other woodwork so that at least every two students will 
have the object on the drafting table. 



VI PREFACE 

Some of the drawings offer good exercises in making 
detail sketches of each piece in the object. Good practice 
can be had also in getting out the bill of material of the 
lumber required for some of the objects shown. The 
workbench or the pig cot furnishes the beginner a good 
exercise along this line. 

While the book is designed primarily for use in the 
drafting room, the exercises shown are such as to be of 
value for use as a course in practical wood shop in schools 
of agriculture. 

The writer believes that the time will soon come when 
our schools and colleges will consider elementary mechan- 
ical drawing at least equal in educational value to free- 
hand drawing. 

L. J. SMITH. 

March, 19 17. 



ESSENTIALS IN 
MECHANICAL DRAWING 



ESSENTIALS IN MECHANICAL 
DRAWING 

MECHANICAL SKETCHING 

Introduction. — Mechanical drawing is, in these days of 
careful planning, the basis of all constructive work. The 
building of ships, the erection of the home, the large fac- 
tory, or the sky-scraping office building, the construction 
of large locomotives, or of any of the great public works, is 
always preceded by very careful and complete drawings 
previously planning all arrangements in detail. 

A knowledge of mechanical drawing is not only essential 
in the constructive trades and professions, but it is of 
value in almost all walks of life. The newspapers and 
magazines make wide use of drawings. Educational 
books dealing with the more practical phases of life are 
illustrated in this way. Indeed, the general public will 
never get the benefit of many of the new ideas, nor be able 
to give others the benefit of their own experience, with- 
out sotne knowledge and use of mechanical drawing. 

It is not necessary to take a long course of instruction 
in order to be able to make or understand ordinary draw- 



2 ESSENTIALS IN MECHANICAL DRAWING 

ings. The making of six or eight pencil sketches will be 
sufficient to give the ordinary student a general knowledge 
of the subject. He will, of course, not become an expert, but 
he will have laid a good foundation for future development. 

Neither is it necessary to have an expensive set of in- 
struments in order to make sketches and learn to inter- 
pret drawings. With a good foot rule graduated into 
sixteenths of an inch, a compass fitted with hard lead, a 
fairly hard drawing pencil (3 or 4 H), and an eraser, it is 
possible with very little expense to make quite complicated 
drawings in lead, and to learn a great deal about lettering 
and drawing in general. 

What mechanical drawing is. — In ordinary free-hand 
drawing where the work is done in " perspective," making 
picture drawings of the objects, the drawings usually 
show three sides of the object, or enough to completely 
represent it, in the one view. In mechanical drawing, 
the thing represented is shown by means of two or more 
views, each view showing one side of the object. In this 
kind of drawing, therefore, several views of the object 
are necessary and must be studied in relation to each 
other, in order to give a proper conception of that object. 
As an illustration, consider the object shown in Fig. i, in 
one view only. In this drawing the eye sees three sides 
of the block at the same time and readily understands 
what is represented. A complicated drawing to accurate 
scale cannot readily be made showing three sides of the 
object, and so the idea of separate views has come into use. 



MECHANICAL SKETCHING 3 

Names of views. — Figure 2 shows a mechanical drawing 
of the same block, which is 2" ^ long, f wide, and f high 
on one side, and f high on the other. T represents the 
top view or plan of the block, 5 the side view or side 
elevation, and E the end view or end elevation. It will 
be noticed that the views are in line with each other. 




Figure i. 

that is, the top view is directly above the side view, and 
the end view is directly to the right of the side view, 
as shown by the light dotted lines which in practice 
are not drawn. The lines a and h will be parts of the 
same vertical line, and c and d of the same horizontal 
line. 

^ The two short dashes above at the right of a number denote inches, 
while one dash means feet. 



4 



ESSENTIALS IN MECHANICAL DRAWING 



The terms ^' plan " and ^' elevation " are used in con- 
nection with architectural drawings and many civil en- 
gineering drawings, while the word " view " is commonly 
applied to other mechanical drawings. In plans for 
buildings, the drawings of the various lay-outs of each 
floor are called floor plans — first-floor plan, second-floor 



-Q 
^ 










n 


T 














^^ 




5 




E 




c 




cf 





Figure 2. 

plan, basement plan, etc. Sometimes the side, top, and 
end views are not sufficient, in which case a drawing is 
made showing part of the object cut away, and this 
drawing is called a ^' sectional view." In reality the floor 
plans of a building are sectional views, showing what 
would be seen if the upper part of the building were cut 
away down to the center of the windows of the particular 
floor plan sho\vn. 



MECHANICAL SKETCHING 5 

Position of the eye in relation to the views. — In mechan- 
ical drawing, if a top view is wanted, it is supposed to be 
drawn as seen by the eye placed directly above the object ; 
if a side view is being made, the eye must view the object 
from that side ; or if the end view is necessary, it is rep- 
resented as if the eye were looking directly at the end of 
the object. The eye is supposed to be far enough away so 
that the rays of light coming from each point on the side 
of the object shown enter the eye in parallel lines. This 
must be continually kept in mind by beginners. 

Isometric drawings. — The isometric drawing affords one 
of the most common methods of showing an object mechani- 
cally in one view only. In this type of drawing the object 
is drawn as viewed from such an angle that all edges of 
rectangular objects are cut down from their true length the 
same proportionate amount. Because of this fact the lines 
are commonly drawn the same length as the lines of the object 
represented. Figure 3 represents an isometric drawing of 
a half dovetail joint. The rectangular edges are usually 
drawn vertically, or 30 degrees from the horizontal (see 
Fig. 4) ; the vertical edges of the object being drawn verti- 
cal, and the edges running lengthwise and crosswise are 
drawn at an angle of 30 degrees from the horizontal. All 
other lines are obtained by reference to the lines represent- 
ing rectangular edges. 

The parallel lines of an object are shown parallel in 
isometric drawings instead of sUghtly converging as they 
do in perspective drawings. On account of this fact, 



6 ESSENTIALS IN MECHANICAL DRAWING 

isometric drawings of large objects do not look natural, 
and the use of these drawings is limited to smaller articles ; 
but they are very serviceable in conveying ideas to those 
who are not able to understand mechanical drawings. 

HALF DOVE TAIL JOINT, 
Scafe Name. 




Figure 3. 

To get the angle of 30 degrees where no 30 degree tri- 
angle is to be had, use the protractor ; or in case none is 
at hand, draw an equilateral triangle with one side vertical 
to an imaginary horizontal Hne ; the other two sides will 
be at an angle of 30 degrees with this line. 

One can buy pads of 9'' X 12'' isometric section paper 
which is lined horizontally and vertically into squares, 



MECHANICAL SKETCHING 



and which has lines also running each way at an angle 
of 30 degrees with the horizontal. 

The angle iron in Fig. 4 is a very simple example of this 




8 ESSENTIALS IN MECHANICAL DRAWING 

type of drawing. It also gives the method of putting in 
dimensions. 

Where the isometric drawings are made of cylindrical 
objects, the circle appears as an ellipse which is usually 
drawn by an approximate method. First draw an isomet- 
ric square whose sides are the same length as the diameter 
of the circle. The ellipse will be drawn tangent to the center 
of the sides of the square at c, e^ d, and /. Draw line ab 
and Knes cd and ef. Draw ch and gd, and these lines inter- 
sect ab at i and 7 respectively. With these points i srndj 
as centers, draw curves ce and df. Then with points g and 
h as centers, draw the curves ed and /c, completing the 
ellipse. 

It is not difficult to make an isometric drawing of curved 
surfaces or edges. Figure 5 illustrates a common method 
of procedure. The end view and the end of the isometric 
drawing are divided into the same number of spaces. 
The lengths of the lines i, 2, 3, etc., are measured on the 
end view of the mechanical drawing or the end of the 
object itself. Then the lengths are transferred to the ends 
of the isometric drawing, thus locating points on the curve. 

Size of drawings. — Objects are represented on paper to 
different scales or sizes, depending on the size of the paper 
and of the object to be shown. Small objects are generally 
represented in the drawing in full or actual size. Very small 
objects may be magnified and shown on paper double their 
actual size. If the drawing is half size, the scale will be 
" 6 inches equals i foot," meaning that 6 inches of the 



MECHANICAL SKETCHING Q 

drawing represents a foot of the actual object. The follow- 
ing are equivalent sizes and scales : — 

Size Scale 

One half &' =i' 

One quarter 3" = i' 

One eighth i|'' -= i' etc. 

If a drawing is made full size, the scale is not put on the 
drawing, but simply the words " Scale, full size." In 




Figure 5. 

architectural work and in other drawings representing 
large objects, the scale is very often as small as i'' = 1'. The 
ordinary rule with the inches divided into sixteenths 
answers very well for quite a wide variety of scales in 
mechanical sketching. If one is doing a good deal of this 
work, however, it is better to buy the regular triangular 



10 ESSENTIALS IN MECHANICAL DRAWING 

rule, which has twelve different scales on the one piece of 
wood. This rule, however, should never be used as a straight 
edge for drawing lines. 

Dimensions. — No matter to what scale the drawing is 
made, the full dimensions are put on the drawing. This is 
very important. For example; if a drawing were made 
half size, and if the dimensions put on the drawing were also 
all reduced by half, then the drawing itself would be a full- 
size drawing of an object only one half as large as the one 
to be constructed; and, if so used, would result in the 
object being made half size. 

As far as practicable, the dimensions are put at the 
bottom, and to the right of the various views : this, how- 
ever, is not a fixed rule. Where there are a great many 
dimensions they are placed on all sides and often across 
the view itself when it does not confuse the drawing. In 
any case, the dimensions should not be crowded too close to 
the lines which represent the various views. 

Figure 6 illustrates the proper method of putting in dimen- 
sions. A short dash and a longer one are put in, these being 
called '^ witness or projection lines." Then lines, called 
*' dimension lines,'' are drawn from the centers of the longer 
dashes, and the dimension is put in at about the center, as 
shown. Arrows are drawn at the points where the dimension 
lines touch the witness lines. The tip of the arrow should 
just touch the witness line. In the case of the 2'' dimension 
shown in the illustration, the distance is indicated as being 2" 
from the point of one arrow to the point of the other ; and, 



MECHANICAL SKETCHING 



II 



as the witness lines are the same distance apart as the ends 
of the block, the dimension shows the block to be 2" long. 
Often, as in the case of the \" dimension, there is not sulBS.- 
cient room between the witness lines for both the dimension 
and the dimension lines, in which case the dimension is put 
inside and the dimension lines and arrows outside the wit- 




FlGURE 6. 

ness lines ; but the meaning is the same. It is f ^' from 
the tip of one arrow to the tip of the other, whether the 
arrows are on the inside or on the outside of the witness 
lines. In still another instance where there is very little 
room between the witness hnes or between two lines whose 
distance apart is to be given, both dimension lines and 
arrows and the dimension may be put outside the two 
lines, as shown in the \'' dimension. Fig. 7. The f dimen- 



12 



ESSENTIALS IN MECHANICAL DRAWING 



sion, shown in the upper right-hand corner of Fig. 6, shows a 
method of putting in a dimension very common with be- 
ginners, but one which is not considered the best practice. 
How to make the arrows. — The arrows are not so easy to 
make as one might think. Properly made, they are at 
least twice as long as they are wide at the barbs, and are 















8 




2. 




7 ^- 




^ \ 




W/,.,. ^ 












5. ' 




G. ' 



Figure 7. 

made slightly curved, as shown by arrow i, Fig. 7. Arrow 

2 is in common use. It is made more easily, perhaps, but 
it is not so artistic and might lead to confusion where a 
number of witness lines or lines of the drawing are very 
close together. It has the objection also that it is likely to 
be the first thing that catches the eye at the first glance over 
a drawing, whereas the views should be first seen. Arrow 

3 is not symmetrical about the dimension line. Arrows 4 



MECHANICAL SKETCHING 1 3 

and 6, shown in Fig. 7, illustrate incorrect shapes. Arrow 5 
shows a very common mistake made by beginners in draw- 
ing, — that of not having the point of the arrow touch the 
witness line. Before starting a drawing make a dozen 
or more arrows, trying to make them as nearly as possible, 
symmetrical with respect to the dimension lines. There is a 
tendency on the part of beginners to make the arrows too 
heavy on account of the fact that they cannot at first be put 
in by a single stroke of the pencil, but must be gone 
over several times in order to get the proper shape. In 
making arrows, therefore, make the strokes of the pencil 
very light, and avoid making the arrows too large and 
prominent. 

Relation of border line to views. — When beginning a 
sketch of an object, first figure out the size of the views 
according to the scale to be adopted, and try to get the views 
in the center of the paper. It is customary to put in a 
border line which is first put in very lightly ; then if the 
various views do not come quite in the center of the border 
line as desired, and if there is plenty of paper outside the 
border line for trimming, it can readily be shifted- a Kttle 
in any direction desired. The border line acts as a frame 
around the object shown, and for that reason should be made 
heavy, the heaviest weight line of any on the drawing. In 
some civil engineering drawings and in map work, two lines 
are often drawn and fancy corners are put in. Do not let 
any part of the drawing or the lettering touch the border 
line, and do not put printing outside the border line. 



14 



ESSENTIALS IN MECHANICAL DRAWING 



Penciling. — At first make the pencil lines of the drawing 
very light ; then when the drawing is completed and one is 
sure that there are no mistakes, the hnes can be gone over 
again and made heavier where they are not to be inked-in. 
This practice will save a good deal of erasing, and, there- 
fore, will save time as well as assist in securing neatness, 
which is an important consideration in any kind of drawing. 
Heavier lines make a drawing stand out more clearly and 
give a much better appearance. The witness Hnes and 

dimension lines should 
always be put in much 
Kghter than the lines of 
the drawing. When 
looking at a properly 
constructed drawing 
the first thing that the 
eye should see is the 
drawing itself, because 
of its greater weight of line ; then, as a secondary con- 
sideration, the eye sees the witness and dimension lines 
and arrows. 

Putting in curves. — When a corner in the view is to be 
rounded off, it is properly done by one of two methods. 
Suppose a right-angled corner is to be rounded with a curve 
of \" radius. Set the compass to i". Place the point at 
the corner a (Fig. 8), and strike off two arcs on the lines 
forming the corner. Then, with these intersections as 
centers, and with the same radius, strike off two arcs which 




Figure 8. 



MECHANICAL SKETCHING 1 5 

meet at b, which locates the center for drawing the i" 
curve. Where the Hnes do not form a right angle, the 
method of procedure is somewhat different. If, as in Fig. 
8, a i^' radius is required, draw light hnes parallel to and 
"g-^' from the lines on which the curve is to be drawn. The 
point c at which they meet is the center* for the curve. 
This last method can be used with the right-angle corners. 

When to use a solid or dotted line. — The following is a 
very good rule for the beginner to keep in mind when working 
on a mechanical drawing. Whenever two plane surfaces 
meet, forming an edge on the side of the object shown in 
the view, there is a solid line in that view. It makes no 
difference whether the surfaces meet at a right angle or at 
any other angle. If the two surfaces do not meet, making 
an edge, but rather round off with a considerable curve, 
then no line is shown except where one of the plane surfaces 
is parallel to the line of sight. Where two surfaces meet, but 
on the far side of the object so that the eye cannot see the 
intersection, the soUd line is not drawn but a dotted line 
is used, as shown by line 7, Fig. 7. These rules are very 
important, and a careful observation of them will assist 
greatly in mechanical drawing. 

How to make hidden lines. — In making these dotted 
lines, called " hidden lines '' or " invisible lines,'' the dots, 
or rather dashes, must not be made too small nor too 
large. In ordinary drawings the dashes are made about 
one eighth of an inch long ; on large scale drawings a little 
longer, and on the small scale drawings they should be made 



1 6 ESSENTIALS IN MECHANICAL DRAWING 

shorter. In any case the dashes should be all of the same 
length. The spaces between the dashes should be uniform 
and should not be more than one half the length of the 
dashes. Hidden lines should not be made as heavy as Ihe 
solid lines of the view. 

Center lines. — When drawings are made of cylindrical 
or partly cylindrical objects, a center line is drawn in the 
side view through the center of the cylindrical part, and 
extends on through the end view of this part. Line 8, 
Fig. 7, shows the proper center line. 

Breaking dimension lines. — If the dimension lines are 
very long, it is a common practice to break them up into 
two or even three long dashes, but this practice should not 
be carried too far. It is very seldom that more than two 
dashes should be put in as dimension lines on either side 
of the dimension. 

Putting in large dimensions. — Where the dimension is 
greater than 36 inches, the length of the carpenter's rule, 
it is often not put down in inches, but in feet and inches. 
For example, 79 inches would be shown on the drawing as 
6' — 7". A very common mistake is to leave out the dash 
between, thus 6'f'. The objection to this practice is that 
the workman who might be making the object from the 
drawing is apt, in the hurry of the work and the possible 
worn condition of the much-used copy of the drawing, to 
make a mistake and make the object 67'' instead of 79'' 
long. The writer recalls seeing mistakes of this kind 
which usually proved expensive. When making drawings 



MECHANICAL SKETCHING 1 7 

to be used by workmen, make it a practice to give every 
necessary dimension, for if it is necessary to add or sub- 
tract other dimensions to get what is wanted, there is 
always a chance of an error which might be costly. 

The printing in of dimensions, explanatory notes, and 
the title constitutes the last, but by no means the least 
important, part of the drawing. Long after the beginner 
has acquired considerable faciUty in the making of good 
drawings, his lettering and figures will betray his inexperi- 
ence. 

Lettering. — There are four important things to be kept 
in mind when lettering. The first point is to have all the 
letters of a uniform height. In order to accomplish this 
readily, it is necessary to draw parallel lines to indicate the 
desired height of the letters or the figures. These lines 
should be drawn as lightly as possible, especially in case the 
drawing is not to be inked-in afterwards or traced for blue 
prints. By the use of the parallel lines the height of letters 
is sharply defined and there is no difficulty in getting uni- 
formity in this regard. 

The second item is that of making all the letters or figures 
of the same slant. In the system of lettering which is to 
be used (Fig. 9), the letters and figures are to be made with 
a slant of about 30 degrees from the vertical. It has been 
found that the slant system of lettering can be printed much 
faster than the old vertical system. On account of this 
fact, the tendency in modern mechanical drawing is to 
throw aside the old vertical system and more and more to 



1 8 ESSENTIALS IN MECHANICAL DRAWING 

use the slant. There is another reason for the use of the 
slant system of lettering. A little difference in the slant 
of the letter or figure is not nearly so noticeable as a corre- 
sponding difference where the vertical system is used. The 
eye seems naturally to be trained to notice anything that 
is out of the vertical, but a slight variation in any given 
slant is not so readily observed. 




Sffi^E^^^ 



n.hrflt->lnf)nklrrir)nrrq-r 
sl ij \/wyy/ 

Figure 9. 

Some difficulty is experienced by beginners in getting the 
proper slant for such letters as X and F. The easiest 
method of accomplishing this at the start is to draw a light 
line at the proper slant, representing the center of the 
letter, and then to make the letter symmetrical about this 
line. 

The third thing to be kept in mind in developing a good 
system of lettering is the item of spacing. This requires 
considerable care at the start ; but, after some experience 
has been gained, letters and figures will be properly spaced 



MECHANICAL SKETCHING 1 9 

without much thought. The letters should not be put in 
at an equal distance apart, but the distance between the 
letters should be such that the space or area between the 
letters is equal. To illustrate, — the capital letters L and 
M must be as close together as possible where the L pre- 
cedes the M , in order to get anything like uniform spacing. 
A glance at the sample lettering will show the necessity for 
carefully considering the spacing on account of the in- 
equality in shape of the various letters and figures. In 
Fig. 9, the spacing between the capitals F and G is too 
great. 

The fourth requirement is that the letters and figures 
should have the same weight or thickness of line. This is 
essential, not only in the more difficult work of inking-in 
letters and figures, but also in the pencil work. In ordi- 
nary lettering for mechanical drawings, no attempt is made 
to shade either letters or figures. 

The main objects to be kept in mind in learning lettering 
for mechanical drawings are simplicity and speed as well as 
good appearance and clearness. 

Figure 9 shows a system of lettering that is in very common 
use. Note the simplicity of the letters. There are no 
extra curves, only just enough to indicate the letters. This 
type of lettering is clear cut, can be read easily, and can 
be penciled in with speed when once mastered. As in 
any system of lettering, the exact shape of the letters must 
be memorized. To this end it is well to have at least one 
memory test in lettering the alphabet early in the drawing 



20 ESSENTIALS IN MECHANICAL DRAWING 

course in order to be sure that the proper shapes are being 
acquired right from the start. 

For ordinary drawings, the capitals and the higher of 
the smaller letters are made i^e'' high, while the smaller 
letters are put in ^^^ high. The proper proportion is to 
make the body of the small letter three fifths the total 
height of the letter. For example, the body of the small 
letter b is three fifths of its total height. This, however, 
is a proportion which is rather hard to get, and the propor- 
tion of i and t6 works out very well and, if anything, 
gives a bolder and -more rounding shape to the letter. The 
possible criticism to the letters and figures shown is that 
they are not broad and full enough. This is more ap- 
parent in connection with the capitals and the figures. 

In putting in dimensions, the figures are ordinarily 
printed i'' high. If a fraction is used, each figure in the 
fraction is sometimes printed a little smaller, about -^ of an 
inch in height, three quarters the height of the full number. 

Good lettering cannot be done with a dull or very soft 
pencil. Sharpen the pencil to a long point and have a 
small piece of fine sandpaper at hand for keeping the point 
in good condition. It is of equal importance to keep the 
pencil sharp when making the drawings. 

Titles. — The title of a drawing is variously located. 
The ordinary drafting office practice is to have the title at 
the lower right-hand corner. Figure lo shows a simple form. 
The name and date are i^" from the lower border line. The 
lettering has yi^" spaces between. The name of the object 



MECHANICAL SKETCHING 21 

shown in the drawing is put in capitals ^ while in the case of 
the name, the scale, and the date, small letters are used. 
Often the title is located above the view or views as in case of 
Fig. i8 and Fig. 20; and sometimes it is placed in the center 
of the paper directly below the views as in Fig. 17. The im- 
portant thing to be kept in mind when penciling in the title 



TABLE BOOK RACK 



Scale: g"^ /'. 



v>|<e 

'^Name.^ Date. 

K)|C3 ♦^ 



Figure 10. 

is to make it symmetricaL If, as in Fig. 10, a center line 
were drawn vertically through the center of the name of the 
object, the line being equally distant from T and K^ the 
other words in the title should be symmetrical about this 
center line. In the figure, the capital letter N in ^^Name^' 
will be as far from the center line as the small letter e in 
" Date." No matter where the title is located, this prac- 
tice should be followed. 



SUGGESTIVE OUTLINE FOR A SHORT COURSE 
IN DRAWING, USING PENCIL AND RULER 

Drawing periods. — There should be one drawing period 
a week if home work is given, or two periods without home 
work. Drawing periods should be one and a half to two 
hours, preferably two hours ; each drawing to be done in 
one period, except the House Plans, which would require two 
or three periods. In case hour periods have to be used, 
two such periods would equal one of the longer ones. 
Definite instructions, by means of a rough sketch on the 
blackboard as to the location of the views in relation to the 
border line and a few of the main dimensions, will save 
much time. See Fig. ii. 

Kind of paper to use. — If the drawings are to be done 
with a rule and pencil only, the edges of the paper used 
must form a rectangle with square corners, as the main 
outline of the drawing will have to be put in by measuring 
from the edges of the paper. A good quality of fairly heavy, 
smooth, white linen bond paper, 8i'' X ii'', is satisfactory 
for these exercises, or, better still, pads of the heavier white 
drawing paper of about the same size, or preferably a 
little larger, which can be had through the bookstores. 
The drawing can be done on any smooth table or desk; 



OUTLINE FOR A SHORT COURSE IN DRAWING 



23 



sometimes it helps to have an extra sheet of paper under- 
neath. 

DRAWING EXERCISES 

Exercise i. — • (Home work.) Hand in a copy of the 
sample lettering in lead pencil, on a specified size sheet of 




Figure ii. 

paper, or on a small uniform size sheet given out for the 
purpose. Make height of letters and figures the same as 
in Fig. 9. 

Exercise 2. — Make a mechanical drawing of the half 
dovetail joint, using the dimensions in Fig. 3 and showing 



24 



ESSENTIALS IN MECHANICAL DRAWING 



top and side views as in Fig. 12. Use the scale, 6'' =1'. 
Put in all hidden Unes. Put in a border Kne i'' from the 
edge of the paper. Put title in lower right-hand corner, 
following the method shown in Fig. 10. Get the views in 

the center of the paper. 
Exercise 3. — (Home 
work.) Hand in an iso- 
metric drawing of the 
half dovetail joint. Scale, 
6'' = i'. Put in all di- 
mensions, but do not 
put in a border line or 
show hidden lines. Title 
and its location as in 
Exercise 2. 

Exercise 4. — Make a 
half size isometric draw- 
ing of the mortise and 
tenon joint from Fig. 13, border i'' from the edges of the 
paper, title at the top as in Fig. 3. Draw all hidden lines, 
but not the parts of the joint separately. 

Exercise 5. — (Home work.) Hand in an isometric 
drawing of a bench hook (Fig. 14). Do not use a border 
line. Put title in lower right-hand corner. This bench 
hook is made from one piece of wood. Read over the notes 
on isometric drawing, beginning on page 5. 

Exercise 6. — Make a mechanical drawing of the 
blacking stand shown in Fig. 15. Scale, 3'' =1'. Border 



Figure 12. 



OUTLINE FOR A SHORT COURSE IN DRAWING 



25 



line, f X 10^'. Draw the views f from the side border 
lines. The body of the box is 16'' long and 11'' wide. 
Make the stand a convenient height for use. Work out 
all dimensions. On a separate sheet of paper hand in a 



- — H^— 






h-^^'H 



1 ' "0103 


i 



l-/#--l 




Figure 13. 

bill of the material required to make the blacking stand, 
using the form given below. The pieces must be of dimen- 

Name of Object 
Kind of material To he finished with 





No. OF Pieces 


Thickness 


Width 


Length 











26 



ESSENTIALS IN MECHANICAL DRAWING 




sions large enough to allow for finishing to required size 
in the wood shop. For example, a 12'' board would be 
used for the vertical end pieces; in actual practice the 



OUTLINE FOR A SHORT COURSE IN DRAWING 



27 



J board will be about iif wide. Timber is sold as 6", 8", 
10'', 12'', 14'', etc., wide, but when actually measured it 

I usually is i^^ less. A i^' finished board is actually about yf " 
thick. In the rough it is about i" thick. An ordinary 2'' 




Figure 15. 

X 4" finished on all sides (S2S) is actually about if" X 
3f " ; the 2" X 6" is if X 5f ". These points must be 
kept in mind when planning the dimensions of wooden 
objects in order to economize in material. Many good 
draftsmen neglect this important matter. 



28 



ESSENTIALS IN MECHANICAL DRAWING 



Exercise 7. — (Home work.) Hand in a mechanical 
drawing of the wooden work basket, a suggestive outline 
of which is shown in Fig. 16. It is 26'' high and 14'^ square. 
Scale, 3'' =1'. No border line. Material, oak. Draw a 
side and a top view. Put title in lower right-hand corner. 

Exercise 8. — 
Make a mechanical 
drawing of a poultry 
feed hopper (Fig. 17). 
Scale, 3^' =1.' Use 
no border line. In 
this case there is not 
sufficient room on 
the 8i X ii'^ paper 
to show the entire 
side view ; part of 
the middle is, there- 
fore, taken out, as 
shown by the broken 
lines. This is often 

done in drawings of 

Figure 16. long objects of uni- 

form size and shape. As the slanting board cannot be 
seen, except by hidden lines, in an end view, a sectional 
view is shown as if the box were cut away at ^ — B, Put 
in title as in Fig. 17. 

Exercise 9. — (Home work.) Hand in a mechanical 
drawing of the table bookrack (Fig. 18) on cross-section 



OUTLINE FOR A SHORT COURSE IN DRAWING 



29 




K#fH 



71 







^^,^^ 




1 
1 

1 
1 
1 
1 
-d 

L\ 
1 
1 
1 




5 i 


f 
____ 




>o\^ 






1 










1 





1 ^ 


^ 


Xj 





^ 


iJ 


QD 


Ji 


-V 




•<) 


.^ 




> 


1 ^ 


(} 


1 


! 


<>! 






paper. If the squares are 16 to the inch, let 4 squares 
equal i inch. If the paper has 8 or 10 squares to the inch, 
let 2 squares equal one inch of the object. 



30 



ESSENTIALS IN MECHANICAL DRAWING 



Cross-section paper is very useful for the rough sketching 
of objects, and particularly for making preliminary plans 
of barns or houses. Let agricultural students, instead of 
drawing the table bookrack, make a drawing of the gambrel 

TABLE BOOK RACK. 
Scale:^a^- / /nch Name 



/^ 



A 



r"ii 



n 



Figure i8. 

roof with bracing, as shown in Fig. 19. Draw foundation 
I foot thick. Scale, ^' =1'. Put the following title below 
the drawing : — 

METHOD OF BRACING GAMBREL ROOF 



Scale 



Name_ 



Date_ 



The figure gives a fairly good idea of one method of fram- 
ing the gambrel roof. It also gives a good proportion for 
such a roof, the rafters being equal in length, and the cuts 
easy to work out. The sketch is for a 36' barn. The 
studding, rafters, and braces forming the bent are all 
2 X 6's. There are two kinds of framing, one on each side 
of the center line. The bent shown on the left side is put in 



OUTLINE FOR A SHORT COURSE IN DRAWING 



31 



every fifth or sixth rafter, and of course is the same on both 
sides of the peak, only one half being shown in the cut. The 
sets of rafters between these bents are tied together as 
shown on the right side, with i '' X 6'' stuff. The hay track 




Figure 19. 

can be hung from the intersection of the scissors truss, if 
desired, or a 2'' X 6'' collar tie can be used at the same 
, level as the intersection just mentioned. The lower 2" X 
6^' brace, that projects out into the loft at the bottom, is not 
always used, as it cuts up the loft to a certain extent. It 
would not necessarily have to extend out as far as shown. 



32 ESSENTIALS IN MECHANICAL DRAWING 

In wide barns the brace should not be left out. Often 
two studs are used at each bent, and it is a good practice 
when building barns much over 30 feet in width and 
height. 

Exercise 10. — (For boys.) Make a copy of the plan 
of a barn shown in Fig. 20. Scale, |'' =1'. Make the 
outside walls i foot thick. Put title in center above the 
plan. 

Figure 20 shows an excellent type of dairy barn. It is 
the plan of the model dairy barns used on the Alberta 
Experimental Farms located in different parts of the Prov- 
ince. The plan shows a central feed room in the most 
convenient relation to the feed alleys. The grain bins 
are overhead in the loft. The plan can be readily extended 
or rearranged. If one wanted an inclined driveway into the 
loft, it could easily be arranged just outside the bull pen, or 
at the opposite end of the feed passage. A root cellar could 
then be put under the incline. It could be extended to 
the left enough to take in the feed passage, thus affording 
a convenient entrance to the root cellar. If desired, a 
concrete milk room could be put under the driveway. The 
cross feed passage at the end makes it very easy to put on 
an additional wing at either side, making an L-shaped 
barn, with the added space available either for more cow 
stalls, or for a horse barn, if so desired. Again, a root cellar 
might be placed at one end of the cross passage, and a silo 
at the other ; the silo being placed on the sunny side of the 
barn. The farmer might cut down the width a little, if 



OUTLINE FOR A SHORT COURSE IN DRAWING 



33 




34 ESSENTIALS IN MECHANICAL DRAWING 

he SO desired, by economizing in the width of the feed 
passages. The barn has the gambrel roof that is being 
used so widely in modern barn construction. 

(For girls.) Copy two plans of the model kitchens in Fig. 
21. Scale, j^ = i\ Put title ''Model Kitchens/' etc., 
in lower right-hand corner. 

The kitchen is said by many women to be the first con- 
sideration in house planning, since it is the part of the house 
where they do a large part of their work and where there 
is the greatest necessity for convenience and comfort. It 
should, therefore, be carefully thought out, and there should 
be no great difficulty in securing a house plan that the 
kitchen will fit into. If the house is planned without par- 
ticular thought about the requirements of the kitchen, it 
often develops that the rest of the house will not admit 
of a convenient kitchen lay-out. 

The suggestive plans in Fig. 21 are from well-known 
women writers on household science. Plan i is from the 
Efficient Kitchen by Georgie Boynton Child. Plan 2 is 
from The Farm Kitchen as a Workshop, U. S. Farmers' 
Bulletin No. 607, by Anne Barrows. Plan 3 is from Mrs. 
Fredrick's book The New Housekeeping, This is an espe- 
cially suggestive plan, as it shows by arrows the cycle of 
operations in the preparing of food for the table, and the 
washing and putting away of the dishes after the meal is 
finished- The kitchen in the plan shown in Fig. 22 is one 
which allows for good light and air as Well as for convenience. 
Make the kitchens whatever size you consider best for your 



OUTLINE FOR A SHORT COURSE IN DRAWING 



35 





..... ... 1 


^ 


/^'-/9'o\ 




^j9^A 






c^ 


/ 




^ 




' / 


J5 


;: 




k t^-^ 


5 


^5 


1 


t\ \^ 














-^ 



•0 





1 ^ 


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. 


1 




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.^ 




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^^ 


^_ 1 





^" 







36 ESSENTIALS IN MECHANICAL DRAWING 

home conditions. The dimensions of kitchen furnishings 
on page 38 will be of assistance. 

Exercise ii. — (Home work.) Hand in a mechanical 
drawing showing side and end views of a table, bookcase, 
or dresser. Scale, iV = i\ If there is room, put in a 
border line. Draw a line representing the floor on which the 
object rests. Put title below the view. 

Exercise 12. — Copy the floor plan of bungalow shown 
in Fig. 22, or some other plan of a bungalow or house. 
Use the scale, j^ = i'. 

In drawing floor plans of a wooden house, make the walls 
6'^ thick — both outside and partition walls. Single 
windows are 28'' to 30'' wide ; large front windows are 3^' to 
4' wide. The front door is usually 36'' wide ; the outside 
kitchen door 30'' ; the double swinging door between the 
kitchen 28'' to 30'' ; doors to bedroom closets 24'' ; door 
to bathroom 26'' to 28'', and other doors 28". These are 
average sizes, though there is considerable variation. 

Stairs vary widely in dimensions. Where there is room, 
a very good stair is one with a 7'' rise, and a 10'' tread. A 
7^" rise and a gi'' tread gives an easy running stair. Cellar 
and attic stairs are steeper, in many cases the rise and tread 
being equal, as 8^'^ for both rise and tread. 

In house planning, doors are usually located in the comer 
of the room. Doors and windows in bedrooms should be 
so located as to avoid drafts across the bed. 

Sizes of furnishings. — The following is a list of common 
furnishings, together with their average dimensions, and 



OUTLINE FOR A SHORT COURSE IN DRAWING 



37 



lAJOJ^ 






a 



..TJ 



TZZJ 



" \ — 



«: 






P 









/ v^ 



11 



to ^ 






q:] 



38 



ESSENTIALS IN MECHANICAL DRAWING 



is useful for consideration in planning the sizes of rooms 
and location of doors and windows : — 



Double Bed 4 

Single Bed 3 

ChHd'sBed 

Dresser 

Dining Room Table 

Living Room Table 

Bookcase 

Piano 

Davenport 2^ X 6 to 7 

Bathtub 2j X 5 

Range 2I X 4 

Kitchen Cabinet 2X4 

Kitchen Sink ij X 2 

Drain Boards to Sink li X 2 

Refrigerator if to 2 X 2^ 



to 4^ X 6 
to 3i X 6 
2^ X4i 
if X3i 
3^X6 

iiX3i 

2iX 5 



feet 
feet 
feet 
feet 
feet 
feet 
feet 
feet 
feet 
feet 
feet 
feet 
feet 
feet 
feet 



MECHANICAL DRAWING WITH REGULAR 
DRAWING EQUIPMENT 

Equipment. — For this work, the following equipment is 
necessary : drawing board i8" X 24", a T square, a 30°- 
60^ triangle, a 45° triangle, a draftsman's triangular 




Figure 23. 

scale, some thumb tacks, a bottle of Higgins' black ink, a 
set of drawing instruments, and a pencil and eraser. A 
small set of drawing instruments that will do very well 
can be purchased for about $3. Figure 23 shows such 
a set of instruments which consists of a ruling pen, a small 
combination bow compass and pencil, a pair of bow dividers, 
a large compass with a pen and a pencil point and an 

39 



40 ESSENTIALS IN MECHANICAL DRAWING 

extension bar for large circles, and a protractor. The rest 
of the drawing equipment will cost about $3 more. To 
avoid confusion, it is highly desirable that the students 
should put their initials on their equipment. 

The left edge of the drawing board must be true, for 
the head of the T square slides against this edge. Drawing 
boards, when first purchased, generally need '' truing-up '' 
on the edge with a jointer plane. The T square, sliding 
against the edge, is used for making all horizontal lines, 
while the triangles, resting against the blade of the T square, 
are used for making all vertical lines. Draw horizontal 




Figure 24. 

lines with the pencil against the upper edge of the blade of 
the T square. Figure 24 shows the drawing board with T 
square, 30^-60° triangle, and drawing paper, ready to 
begin work. 

Steps in penciling and inking drawings. — i. Put draw- 
ing paper on center of board, fastening with four thumb 
tacks, and having horizontal edges parallel to blade of T 
square. 



DRAWING WITH REGULAR DRAWING EQUIPMENT 41 

2. Draw border line lightly to required size. 

3. Lay out position of views, keeping in mind position 
of title. 

4. Draw main lines of views. 

5. Draw hidden or invisible lines. 

6. Put in witness and dimension lines. 

7. Put in dimensions and arrowheads. 

8. Print in title, and notes if any. 

9. Ink-in border line heavy, 

10. Ink-in curves. 

11. Ink-in views. 

12. Ink-in witness and dimension lines. 

13. Ink-in dimensions and arrows. 

14. Ink-in title and notes. 

Inking-in drawings. — The best ink for this purpose is 
Higgins' Carbon Waterproof Ink. There is also Higgins' 
Black Ink which is not waterproof. The latter is just as 
good except for the reason that sometimes one may be 
carrying a drawing on the board exposed to the air, and a 
few flakes of snow, or drops of rain, may fall on it, in which 
case the ink which is not waterproof softens and, if rubbed 
in that condition, will spread and spoil the drawing. 

Always keep the stopper in the bottle, as it keeps out 
the dust and prevents accidents if the bottle is tipped 
over. When filling the pen by the use of the stopper, do 
not perform the operation above the drawing, as there is 
always danger of dropping some ink ; nor should one fill 
the pen too full nor allow it to get entirely empty. 



42 ESSENTIALS IN MECHANICAL DRAWING 

The first care in inking-in drawings is that the surface 
be free from dust, particles of eraser, lint, etc. Any such 
material is caught up by the pen and will change the 
thickness of the line. Next, and equal in importance, is 
the care of the inking pen, whether it be for the compass or 
for the straight line work. The pen must always be free 
from ink, either wet or dry, on the outside surfaces of the 
two points, and from dry ink on the inside surfaces. Under 
no circumstance should ink be allowed to dry in the pen. 
The piece of linen which comes around the ink bottle is 
for cleaning the pen, but any cloth free from lint will do. 

Before starting to ink the first drawing, examine the points 
of the pen ; they should be sharp and of equal length. %In 
case they are not, make them equal by rubbing them on 
an oilstone. To tell whether they are in good shape, screw 
the points almost together and hold them up to the light. 
When inking, tip the handle of the pen about thirty degrees 
from the vertical (Fig. 25) in the direction in which the 
line is to be drawn, but keep the pen in the vertical plane 
which passes through the line so that both points of the pen 
rest with equal pressure on the drawing paper. If one point 
touches and the other does not, the line drawn will be 
ragged and rough on the side where the point of the pen does 
not touch. Careful attention to this principle will greatly 
improve the work of beginners. 

Use of compass. — When inking with the compass ob- 
serve the rules just given. Hold the compass lightly at 
the extreme end between the thumb and first or second 



DRAWING WITH REGULAR DRAWING EQUIPMENT 43 



finger and make the circular motion by rolling the end of 
the compass between the surfaces of the thumb and finger. 
Do not press down hard. When there are curves to be 
inked-in on a drawing, always ink them first. It is far 
easier to ink-in a straight line to meet one end of an inked 
curve, than to ink-in a curve to meet two straight lines. 

Inking on transparent linen tracing cloth is a little more 
difficult operation than working on paper. The glazed 



Q 







Figure 25. 

surface does not take the ink so readily and the ink does 
not dry so quickly. Many consider it preferable to ink 
on the glazed side, as there is more starch on that surface, 
which permits erasing. Before starting to ink, rub an 
ordinary blackboard eraser over the glazed surface so 
that it will take the ink more readily. Be careful to 
wipe off the chalk before beginning to ink. The majority 
of draftsmen prefer to use the dull side, as it takes the ink 
better. 



SUGGESTIVE LIST OF EXERCISES FOR A SHORT 
COURSE IN DRAWING WITH INSTRUMENTS 

This course will require twenty two-hour drawing periods, 
one period a week. It is well to set a definite time for each 
exercise to be finished, in order that those a little behind 
may catch up with the rest. All exercises to be inked-in. 

Exercise i. — Hand in a copy of the sample lettering 
on a piece of drawing paper 6'' X 8", with a border line 
4'' X 6''. Make letters same height as in the copy. Print 
name at lower right-hand corner inside the border line. 
Use light pencil fines to guide when lettering, and erase 
them after the ink is dry. This exercise is to be done out- 
side of the regular drafting periods. 

Exercise 2. — After laying out Fig. 26 very carefully 
with a sharp lead pencil, start inking it. The large square 
is 5'' each way and is divided into 2^'' squares. The lines 
are all spaced \'' apart at the edge of the squares. To get 
good results, the laying out of the squares and the spacing 
must be done very accurately. The beginner may spoil 
the first drawing, but that is to be expected. Finish the first 
drawing as carefully as possible, even if some parts are not 
satisfactory, as the exercise is for the purpose of giving 
experience in the use of the pens. This experience gained 

44 



SHORT COURSE IN DRAWING WITH INSTRUMENTS 45 

on a small drawing will prevent one's spoiling a more 
complicated drawing later on. 

After the first set of squares has been filled in carefully, 
make a second drawing of the squares. The beginner 
should now have sufficient experience from the first trial 
to do some good inking on the second drawing. When 




Figure 26. 

inking-in the lines that converge to the upper right-hand 
corner in the upper left-hand square, ink the lines to 
within about |'' of the corner; then when all the lines 
have been inked-in, the part not done can be completed. 
By following this method the point at the upper right- 
hand corner will not be lost, and the work can be more 
accurately done. Ink-in the outside of the squares after 
all the other work is completed. Hand in this exercise on 



46 



ESSENTIALS IN MECHANICAL DRAWING 



a sheet 6'' X 8'' without a border line and with name 
neatly printed in ink in lower right-hand corner. 

Exercise 3. — Make a full-size drawing of the wooden 
float in Fig. 27. Size of border line 11'^ X I5'^ Trim the 





















'!5|o 
















c\" , 












i 










1 




Figure 27. 

drawing paper to within V of the border line. Put title 
at top. 

Exercise 4. — Mechanical drawing of blacking stand 
(Fig. 15). Show side view of stand open and end view. 
Follow the general directions given in Exercise 6 on page 
24. Use a border line 11" X 15''. Print out table of 
material underneath the views. 

Exercise 5. — Make an isometric drawing of the bench 
hook shown in Fig. 14, scale full size. Ink hidden lines 



SHORT COURSE IN DRAWING WITH INSTRUMENTS 47 






Figure 28. 



considerably lighter than the solid lines. Put title in lower 
right-hand corner. Border line ii'^ X 15''. Trim all 
drawings to within i'' of the border line. 



48 



ESSENTIALS IN MECHANICAL DRAWING 



Exercise 6. — Drawing of work basket (Fig. i6) or 
umbrella stand (Fig. 28). The work basket is to be 14'' 
square and 26'' high. The umbrella stand is 12'' x 2^', 







♦ 






f 










1 


i 


-fi 


.1 






5 






i" 


- 








1 


' T 


* * r 


^ 




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1 


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1 


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V 


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-itf' 


J"^■^ 



SHORT COURSE IN DR.\WING WITH INSTRUMENTS 49 

Use the scale, s''=i' in either case, and the standard 
border line ii'' X is'' - Show a side view, and top view to 
the right of the side view. If the student has had wood 
shop, show the mortise and tenon joints. Show all dimen- 




FlGURE 30. 

sions. Underneath the top view, print the bill of material 
as already directed. 

Exercise 7. — Make a side and end view of either a work- 
bench (Fig. 29) or a sawhorse (Fig. 30). The workbench to 
be drawn to a scale of i''= i^ Often, when objects are 



5° 



ESSENTIALS IN MECHANICAL DRAWING 




o 



SHORT COURSE IN DRAWING WITH INSTRUMENTS 5 1 

drawn that naturally rest on the floor, a heavy line is 
drawn to represent the surface of the floor. Border line 
11'' X 15". Place title above the views. The sawhorse 
should be drawn to the scale, 3'' = i'. Draw a heavy 
line to represent the floor. 




Figure 32. 

Exercise 8. — ; Draw side and end views of a portable 
pig cot (Fig. 31) with part of the roof boards arid siding 
cut away to show the framing. Scale, f '' = I^ Use the 
11'^ X 15" border line. Place the title above the views. 
Figure 3 2 shows the framework of the pig cot. First draw 
the end view of the frame of the pig cot. The rafters are 



52 



ESSENTIALS IN MECHANICAL DRAWING 





f 


l.,.n. r» n ,n_ 


II , - " " II"" 




1 




. 


I 1 




1 


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tVj 


j&c/c/o^pa9_£ 




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I 


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I 


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Plan. 


CD - 




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8' long over all. Then draw in the roof boards, vertical 
siding, and door. The door is made of two thicknesses of 
inch lumber, one thickness being nailed on crosswise to the 



SHORT COURSE IN DRAWING WITH INSTRUMENTS 53 

other, the outside layer being vertical. The door swings 
both ways on f '' rods as shown. Having drawn the end 
view, lead in the side view, getting the heights of the various 
lines by transferring horizontally across from the end view. 

Exercise 9. — Draw plans of a poultry house 16' x 
25', showing plan, sectional view, and end and side eleva- 
tions as in Fig. 33. Use the scale f'' =1'? and make the 
drawings on paper 18'^ X 24''. Use a border line 15'' X 22'', 
and trim the paper to within f of the border. The pitch 
of the roof is xe? the rafters being given a f rise, instead of 
the half pitch, in order that 12' material may be used for the 
rafters and still give room for the straw loft. The plan and 
sectional elevation show the standard layout for nests and 
roosts for a fresh-air house for 100 hens. Figure :^2> ^^^y ^Iso 
be followed in planning a house for a smaller number of birds. 

Exercise 10. — Draw stable plan, side and end eleva- 
tions of a gambrel roof barn, the scale \^\ tV? or J'' to the 
foot, depending on the size of the barn. Use a sheet of 
drawing paper 18'^ X 24'^ If possible, use a border line, 
the size depending on the amount of space the views take. 

Figure 34 will give suggestions as to the proper method 
of proceeding. First, draw the end elevation, showing the 
framing of the barn. This is the basis for starting the 
drawings as well as for the carpenter work. Next finish 
the left half of the end elevation, showing siding, cornice, 
corner boards, etc. Then draw the side elevation, trans- 
ferring the various heights across from the end elevation. 
The plan of the barn should, of course, be worked out 



54 



ESSENTIALS IN MECHANICAL DRAWING 




SHORT COURSE IN DRAWING WITH INSTRUMENTS 55 

in detail before the elevations are drawn. The plan is 
directly below the side elevation. The space below the 
end elevation can be used for the title, and, if so desired, for 
details of stalls, ventilation systems, etc. The end eleva- 
tion gives the proper proportions for laying out the rafters 
of the gambrel roof. In barns up to 40' or more in width the 
height of the building is commonly made about equal to the 
width. In wider barns the height will not equal the width. 
Exercise ii.^ — Draw the basement and first and second 
floor plans of a modern house, together with a front elevation 
of the same. Use two sheets of paper 18" X 24". Draw 
the first and second floor plans on one sheet and the basement 
plan and front elevation on the other. Use the scale i" = 1'. 
Ink the walls in solid black except for windows and doors. 
Put the title at the top of each sheet. The following is a list 
of items to be kept in mind when laying out a convenient 
basement, though in many cases all are not necessary. 

Stairs, Outside entrance, 

Furnace, Cistern, 

Chimney, Pneumatic tank. 
Soot box in base of chimney, Pumping apparatus, 

Coal bins. Laundry, 

Coal chute, Drying clothes (in winter), 

Wood storage, Vegetable storage. 

Lighting equipment Fruit storage. 
(gas or electric lights), 

^ Should the course in drawing not allow enough time for complete 
plans of a house, the first and second floor plans and basement plan might 
be worked out to a smaller scale on one sheet of paper, leaving the space 
in the lower right-hand corner for the title, similar to Fig. 34. Figure 35 
illustrates the method of laying out the rough plans on cross-section paper. 




Figure ^5. 



SHORT COURSE IN DRAWING WITH INSTRUMENTS 57 

The grading of drawings. — The three points to be consid- 
ered in grading drawings, are i, neatness; 2, lettering, figures, 
dimension and witness lines and arrows ; 3, the actual draw- 
ings. A very good arrangement is to allow 10 points for 
neatness, 30 for lettering, etc., and 60 for the drawings. It 
is a good plan to go over all the drawings, grading them 
for neatness, then go over them again and grade for the 
lettering, etc., and finally run through the drawings the 
third time and grade the drawing. 



